Filtering material and method of preparation thereof



Patented Mar. 22, 1927.

UNITED STATES HENRY A. HILLS, OF GRAN D RAPIDS, MICHIGAN.

FILTERING MATERIAL AND METHOD OF PREPARATION THEREOF.

No Drawing. Application filed July 3,

This invention relates to a new and improved filtering material and the method of pre aration thereof.

The specific method of preparing the membrane used in the filter described and claimed in the aforesaid case is herein set forth.

It is the object (if this invention to provide a filtering material especially for use with l hydro-carbons, as gasoline and the like which shall be absolutely impervious to water.

It is a further object of the invention to provide a filtering material which is simply and easil prepared, is made of inexpensive materia and which therefore can be readily and chea 1y manufactured.

It is still anot er object of the invention to provide a filtering material which does not easily clog up and which will operate efliciently for an indefinite length of time.

Other and further important objects of the invention will be a parent from the following description an specification.

The inventlon (in a preferred form) is hereinafter more fully described.

Process:

I have found by a series of experiments that a fabric impregnated with an essena0 tial oil will permit the passage therethrough of a hydrocarbon oil but will effectually exelude water. Further experiment has shown that the best and most efiicient method of F impregnating the fabric with an essential 85 oil is to mix the essential oil with a mineral oil or any other substance which possesses the property ofdpenetrating the fibres of the refine more rea 'ly than the essential oil itse 40 One particular method of preparation of the improved membrane consists of soaking a fabric which is preferably closely woven, such as cotton flannel or the like, in a mixture of oil of citronella and kerosene for a period of time of approximately one month or more.

The essential oil or oil of citronella renders the fabric impervious to water, and the purpose of the'kerosene or mineral oil is to 6 make the oil of citronella. more fluid and to aid in the penetrating of the fibres of the cloth by the essential oil or oil of citronella.

1920. Serial No. 393,957.

The oil of citronella used is commerciall available and consists mainly of geranio, citronellal, camphene, dipentene, limonene, and traces of linalool, borneol, methyl heptenone, methyl eugenol, and sesquiterpenes.

I have found that some of these substances, or all of them, or their combination, render a fabric impregnated therewith impervious to water, but permitting of the passage therethrough of certain other fluids, in this case hydrocarbons, especially those of the lighter series, as gasoline, the treated fabric actin' in this case in a manner similar to the semi-permeable membranes used in demonstrations and experiments relating to osmotic pressure, or the membranes used in dialysis, which is the separation of crystalloids from colloids, these membranes, as is well known, permittin the passage there through of the molecu es of one substance but efi'ectually excluding the passage of the molecules of some other substance. i

The addition of the oil of citronella to a fabric also hastens the penetration of a hydrocarbon oil, robably because a film of oil of citronella hinders surface absorption of the hydrocarbon oil and facilitates its passage along the surfaces by capillarity. I so Herein is provided a filter for gasoline which effectively and positively excludes the passage of water therethrough and which is not affected by long usage and which is neither contaminated nor sto ped up byany iron oxides or other impurities ordinarily present in water usually held in suspension in-gasoline.

This membrane I have found to be very superior to the chamois-skin membranes 00 ordinarily used as in a recently conducted testone thousand gallons of commercial gasoline were filtered through chamois skin and no water was separated and then the same gasoline was filtered through a iece of canton flannel treated in the manner a ve described, and 15'to 20 gallons of water .tvere separated red with iron oxides from the tanks.

This membrane is further superior to others in that no fine fuzz or bits of cloth or chamois is given off which tends to clog the jet of the carbureter.

I am aware that numerous other oils, and

5 than necessitated by materials may without departing this invention and he used through a wide range from the principles of I therefore do not purpose limiting the patent granted otherwise I claim as the prior art. my invention:

1. A Water proof filtering material comprising a flannel cloth impregnated with oil of citronella.

2. The method filter which cloth with a solution of kerosene and oil of cit-ronella.

3. The method of preparing a water proof filter which consists of saturating a flannel 15 cloth with a. solution of kerosene and oil of citronella and. allowing the said cloth to remain in the oil mixture for approximately 30 days.

In testimony whereof I have hereunto sub- 2 scribed my name.

HENRY A. HILLS. 

